THE DAIRY.

New Zealand Mail, Issue 1247, 23 January 1896, Page 6

THE DAIRY.

MILK: ITS NATURE AND COMPOSITION. Under this specific title, which indeed is limited in its scope, at all events from a scientific point of view, writes Professor Sheldon in an English paper, Dr C M. Aik man has recently given to the dairy world a very interesting and at the same time a true and lucid treatise. The author has been favourably known for some time past as a writer on the nutrition of farm crops, and now he has entered the inner domain, so to speak, of dairying. His previous works on manures, manuring, the sources and uses of nitrogen, etc., etc., are noted for lucidity and simplicity ot language, and these aie the qualities necessary to commend a book for the favourable consideration of men whose business lies within the folds and limits of practical agriculture. And he has now taken up a more delicate and intricate subject, a subject at one refined and attractive, which iss handled in a manner that is sure to win widespread approval. There was, it is true, no scarcity of works dealing with milk as a subject, and some persons may think a new one now superfluous. Such persons, if any there be, mav bo disregarded without any danger, and I will venture to say that Dr Aikman’s handy little volume on milk, complete in ISO pages, will met a want that many persons have long felt for such a book, and will take its place in “ the best hundred books ” appertaining to the wide domain ot agriculture, or at all events to that of dairying. PEOPLE TO WHOM IT WILL RE USEFUL

In this age of progressive dairying, the constituency to which such a book appeals is constantly increasing in numbers. If we look only to the expanding milk trade, and compare its condition now with its condition a quarter cf a century ago, we shall find that the number of men and women who feel the need of instructing themselves as to the nature and composition of the fluid which forms the staple of their business is at least quadrupled. This need has never made itself felt very much amongst dairy farmers who make cheese and butter at home, though there is no real or reasonable excuse for this indifference. But the requirements of the milk trade as to quality of milk, and the prosecutions which have taken place of vendors of milk, whose quality was inferior, have opened the eyes of thousands to the need of tuition on the subject —a need which arises out of a desire for the preservation of their own safety in case of dispute. And if it should come to pass, as seems likely enough, that milk should come erelong to be sold on a basis of quality as disclosed by analysis, or some simpler mode of testing milk, the need for learning still more and more about the nature of the composition of that immensely important fluid will still again increase. Then, in addition to daily farmers pure and simple, we have now an army of dairy teachers and dairy students, to whom such a book is an important acquisition. This little book, indeed, once available, becomes practically indispensable to those who wish to know the best and latest that has been verified in respect of milk, and are aware that such a work is within their reach. Then there are the managers of creameries and cheeseries —if I may coin a word to be used instead of cheese factories —as well as of private dairies which aspiie to he in line with the progress of the day, all of whom may with advantage make this little book the basis of their not infrequent study.

THE FORMATION OF MILK. “ The exact method in which milk is formed in the udder is, as yet, far from having been clearly demonstrated,” we are told ; but at tlie same time it is true that we know more than we did twenty years ago, or even ten or five years ago, and as various eminent men are studying the beautiful problem which appertains to tlie formation of milk in the mammary glands of mammalian animals, it is probable that in course of no long time we may learn, if not all, in any case all that is possible on the subject. That milk is a fluid filtered, as it were, through the animal system, though at the same tyme containing a transfusion of matter from the filter bed, so to speak, is/obvious to any one who has taken thef trouble to think at all upon the subject; but how the process is conducted, aind what are the more immediate sotarces of the solids of milk, are points /that are still unsettled. Milk is of the animal body, equally* with others that might be named-4iwith blood, for ex«

\ ample; bub it is much greater in volume and more rapid in formation than all others that may be likened to it. The rapidity of its transudation into the glands is seen in the large daily yields of milk which are obtained from very many cows. PERCENTAGE COMPOSITION. Dr Aikman tells us that “ the composition of milk of different ” —species of—“animals is practically the same, although a considerable valuation occurs in the proportion in which its different constituents are present,” and lie gives h table containing percentage composition of the milk of fifteen different specieß of mammalia, including—no doubt to the surprise of many folk—one that is not generally known, as a yielder of milk, viz., the porpoise, whose milk, containing 45 80 of fat, is nearly ten times as rich as that of the cow. The elephant comes next with ] 9*57 of fat, and no other conies up to f 0 00, the bitch, the camel, and the ewe being nearest, in the order given. We are most of all familiar with cows' milk, however, and, as a commercial article, it is the only one that is important to ns in this, country. Dr Aikman gives four sets of figures, derived fiom different sources, showing the average percentage of solids in cows’ milk : German, 12*25 and 12*55; American, 13 00; and .English, 12 9; (he 7liiv-n 'average of these is L2'32, or say 12 i-3 pm- centum of solids, and it is doubtful whether we can adopt a closer approximai i->n to the average quality of cows’ mili< than 12 1-3 per cent, of solids. But llie variations in the percentages of solids are very great. Fleischmann puts them at 9*9 to 147 ; Kirchner at 7"2 to 12*63 ; and American authorities at B*6 to 18*9 ; and the mean average of these is B*6 to 15 4. The American variation shows a greater disparity than the others, chiefly, no doubt, because of the milk of the Jersey cattle, which is evidently not within the scope of tests made by Fleischmann and Kirchner. The standard of quality, on which, in this country, the law determines whether or no milk has been interfered with to its hurt, is a total of 11 00 of solids; but it is obvious to any practical man that whilst this standard may be unjustly high in reference to some cows’ milk, it is not enough in other cases. It is clear, too, that the farmer who sells milk will never receive bia due, justly and fairly, until milk is sold on a quality basis. QUANTITy AND QUALITY. We are told that the quantity of milk yielded by a cow depends on the activity of the milk-glands in the udder, and this activity is influenced by a number of conditions, and Dr Aikman cites “ the interesting and well-known fact that, if a cow which has been in the habit of being milked twice a day is milked oftener, the result, is not only that more milk, but milk of richer quality, is obtained than was formerly thecase.” Thisisastrueaaitisimporiant in the way of illustration. It is obvious, for instance, that the way to let a cow dry is to begin milking her once instead of twice a day, and shortly once in forty-eight instead of once in twentyfour hours ; and that a poor hand at milking will soon cause the cow t© yield less is well known to all dairy farmers. In the light of these matters relating to the falling away in milk, the converse of them is true, to a limited extent, in reference to an increase of milk by milking oftener than twice a day—at all events up to the time when the cow is past the height of her milking season. > It is to be "borne in mind that while milking of tester than twice a day will

increase the quantity of milk a cow will yield, instances are on record where the increase has been 20 per cent, in milk, and 27 per cent, in butter fat, by milking three or four times a day. Iso doubt it may be taken for granted that frequent milking will do somethin" to promote the flow of milk in many—and perhaps in most, but not in all—cows, and it will probably tend to lengthen the period of lactation. Such frequent milking will, however, have to be thorough, and at regular intervals, or the result will be different after a time, as it is, indeed, when calves are allowed

to suck from their dams. An increased flow of milk will, from whatever cause, demand an increased supply of richer food, er the cows will fall off in condition Milking at regular hours, night and morning alike, where the almost universal practice of twice a day is followed, is rightly considered beneficial to the production of milk, and thorough milking is necessary to avoid a curtailment of the period of lactation. NATURAL APTITUDE. At tliis point Dr Aikman remarks, page 45 :—“The condition which influences not merely the quantity, but also quality, of milk to the gieatest extent, is the nature of the milk "lands that is to say, the individuality ot the cow. Next to the individuality of the cow may be said to he the breed.” The individual capacity is not necessarily the breed capacity for milk in any given cow. It may be higher or lower, and sometimes the disparity is marked. Not all Jerseys, for example, give very rich milk, ora large quantity of it, and the same may be said of Ayrshire?*, or any other of our dairy breeds. The a vet age breed capacity is beneath the best and above the worst milking cows of any breed. For all that, however, there is much potent influence in breed, for in the case of the Jerseys, the Guernseys, the Ayrshires or the Iverrvs-—four of our smallest but deepest milking breeds —we may expect the chances to be greatly in favour of any heifer turning out a good milker. This could not be said of aiy other breed, but merely that the chances were about even. The breed influence appears to be stronger amongst the small than amongst the large breeds, in reference to copious milking. In every breed, however, as Dr Aikman says, the individuality of the cow—or, as I might say, the natural aptitude of any individual cow must be taken first, for it defines the cow’s capacity for milk, and is not always obedient to breed.

And further, where a cow’s natural capacity for milk is small, forcing with food will make but little impression in the wav of increase in the lacteal fluid ; hut, in instances where that capacity is considerable, an increase and an improvement in the l’oou supplied to the cow will meet with a ready and a satisfactory response. And, not only so, but this considerable natural capacity is susceptible of expansion to a degree far beyond that of cows who are naturally poor milkers. Whatever a cow’s individuality may he, however, breed is a most important influence, for it increases, if it is the right sort, our chances of getting good milkers from our young heifers, and by means of it the individuality spoken of is transmitted from generation to generation. Dr Aikman’s book will meet with much approbation from those interested in dairying into whose hands it may fall.